A character notes, late in John Curran's tense, tragic Chappaquiddick, that history will be the true judge of the fourth of Joe Kennedy's boys. Curran's film, often enthralling and upsetting, represents a welcome break in the hagiographic treatment that Edward Kennedy, the longtime Lion of the Senate, enjoyed in the years leading up to his 2009 death.

Curran, working from a screenplay by Andrew Logan, finds some pathos in Kennedy's failings: his dynastic worries, expressed to Mary Jo Kopechne (Kate Mara), as Kennedy (Jason Clarke) drives her around the twisting roads of Chappaquiddick Island in July 1969; his terror after he careens over a one-lane bridge and into a pond, where the car sinks upside down to the bottom; his paralysis after he swims to the surface but can't bring himself to go back and rescue her or to telephone for help; his abortive flashes of conscience when the film becomes, about halfway through, a dark comedy about a coverup.

The film's drama becomes not whether Kennedy will ever do the right thing, whether he'll admit to the police and the public and Kopechne's family the truth of just what she was doing in the car of a married senator and just why he failed even to try to save her life. Instead, the drama is whether we today, sifting the miserable details, can find any reason not to damn him. Clarke's performance suggests an uncertain husk of a man desperate to haul himself into greatness but incapable of taking action without instruction. And the film suggests, sometimes stridently, that Kennedy had bought the myth of his family's importance -- that his political career actually must matter more than the young woman's life.